Who knew starting point guard Raymond Felton would emerge as the Knicks’ most indispensable player — the engine that ignites the Cadillac. Without him since after Christmas, the Knicks offense has looked like an old Buick station wagon.

The post-Christmas, Felton-less Knicks are a mediocre 5-6, allowing the Nets to crawl within a game in the Atlantic Division race.

When a slumping Felton broke his right pinkie in the loss to the Lakers, he was blamed for everything but the fiscal cliff. He was shooting too much, was hurting the team by playing hurt, was not named Jeremy Lin.

Now the Knicks may get a gift on Saturday in Philly — as Felton eyes his return. He was cleared for practice yesterday, but won’t be permitted to scrimmage until Friday. Felton revealed his pinkie broke in three places.

Asked the chances of manning the point in Philly, Felton said, “Big chance. Big chance. But I can’t speak on that. That’s not my decision to make it. If it’s up to me I’d play [tomorrow in] Boston, but they’re not going to let me do it because there’s a possible chance if I break it again, I’d be out two, three months. I’d have to have surgery on it. Everyone looks at it as, ‘Llittle pinkie. He shouldn’t be out.’ I fractured it in three places. I have three bones that shattered.’’

Felton is as tough an NBA warrior as they come. It took his absence for fans to appreciate him. Jason Kidd couldn’t handle the starting-point guard role — too many minutes, too little penetration. The future Hall of Famer — at 39 — is now better off the ball.

“We missed him a lot,’’ Mike Woodson said. “He’s a big part of the puzzle. We didn’t bring Kidd in to play 30-plus minutes a game. Jason’s giving us all he can give us, and I’m wearing him down.’’

So is Carmelo Anthony, who has shot poorly in four of his last five games. He’s been forced to handle the ball a lot more, forced to do his isolation routine too often, resulting in contested shots.

The frenetic Felton eased the scoring burden on Anthony while creating for him, too. Felton also made life easier for Kidd and center Tyson Chandler, who has missed his pick-and-roll partner, resulting in Chandler violently dunking those lobs at the rim.

“We miss Raymond,’’ Anthony said. “When he was playing, he was playing great, he was controlling the ball. With him being out, it put guys in positions they’re not comfortable with on the basketball court.’’

And then there is the wild card. It was bad luck for Amar’e Stoudemire when he finally made his return Jan. 1 that Felton had just gone down. The chance to see Felton and Stoudemire work the pick-and-roll — like they did seamlessly in 2010-11 before Felton was sacrificed in the Anthony deal — was delayed.

Stoudemire has been scoring in different ways — moving without the ball and cutting to the basket. His touches, though, are low and he’s coming off the bench. Is Woodson waiting to start Stoudemire once Felton comes back? Probably not at first, but it’s at least a stronger option with Felton.

“Raymond’s going to help us a lot,’’ Stoudemire said. “He’s our starting point guard. He helps the offense really facilitate the plays and get in our offensive schemes a lot sooner. He also brings a lot of up-tempo style and a great element back to the game.’’

As a free agent coming off a disappointing season in Portland, the summer market for Felton was dismal. The Knicks got their summer’s biggest bargain in his 3-year, $11 million deal. No poison-pill contract that Lin got in Houston — just a below-market-value deal and the right kind of scoring point guard.

Felton said “it’s been painful’’ being out. He has missed exactly four weeks — his career’s longest absence. Like Anthony, Felton also won an NCAA title — for North Carolina in 2005. It is looking like he’ll be the key to whether he and Anthony can win their first NBA title together.

“We’re asking a lot from those guys,’’ Felton said. “Melo’s doing a lot with the ball now — isos, coming off screen and rolls, posting up.

The Knicks lace ’em up in Boston tomorrow as the Kevin Garnett cereal soap opera takes center stage. But Saturday in Philly is when we can start to truly judge the Knicks again, when No. 2 is reinstalled as the engine.